Must Be That Time
by alwayskate
Summary: Fill for a kink meme (or 2). Read authors note. Takes place in early September. Castle decides he can't go a third night away from Beckett and gets proactive. M for a reason.


This is to fill a kinkmeme over on livejournal... two actually. I've never written or done anything quite like this before but I decided to explore new territory and stretch my own comfort zone. This is definitely rated M, involves period sex, red wings, and a BJ wake up. Don't read if you're not into it! For those who are, please read and review, I hope I did it justice and appreciate constructive criticism. Kind of incredibly nervous about this, so please be gentle!

This story would take place in September, nearly 4 months into Castle & Beckett's relationship.

* * *

It's only 9pm, but it's an unsocial enough hour that she knows only Castle could be knocking on her door. Curled up on the couch with a heating pad, a glass of wine, and her favorite from the Storm series, Beckett curses herself for not giving him a key before this. She had reasoned that being almost four months into a relationship was too soon, but this has her reconsidering. She yells for him to wait a minute as she gathers herself before standing and walking to the door to let him in.

On the other side of the door, Beckett sees Castle carrying a tote bag and a nervous smile. "Castle what're you doing here? I thought we agreed to spend tonight apart." She doesn't mean to sound unwelcoming, but she's got cramps that have been tearing up her insides all day and company wasn't really on her agenda for the night.

Castle's smile doesn't falter but his eyes dim a little before he replies, "Can I come in?"

Only then does Beckett realize they're still standing at her front door. She moves back to the couch leaving Castle to close the door behind himself and follow her. She returns to her seat, sitting on the heating pad by accident before grabbing it and putting it behind her, between her back and the couch arm.

"I'm here because I missed you. We spent the last two nights apart and I wanted to see you," Castle explains himself as he sits down on the chair next to the couch, clearly still a bit nervous about showing up unannounced after she'd told him she wanted to be alone.

"Castle we were together at the precinct all day," she knows she's not being very nice, but since they got together her period has been torture for her; it's the time of the month when she is the horniest and it's also the time of the month when every guy she's been with hasn't wanted to "go there".

Castle's eyes look a bit shifty, like he knows he might be about to step into something and she's intrigued immediately. "Beckett you don't have to hide that you have your period from me," Castle's tone isn't condescending but the statement surprises Beckett.

"Castle I wasn't really hiding it," Beckett replies quickly and from Castle's raised eyebrows she knows he's waiting for her to tell the truth. "I'm not hiding it Castle. We both know I get my period."

Castle sighs, stands, and sits next to her feet on the couch. "I didn't really put it together in the summer because we spent quite a few nights apart with Alexis still at home. But I realized this is the first week since Alexis left that you've wanted three nights in a row away from me." His hands move to her feet, rubbing them gently and her body relaxes a bit. "I don't want to spend three nights away from you, that's why I'm here."

Beckett meets his eyes and smiles at him gently, leaning over her knees to kiss his cheek, "Castle that's very sweet, but I'm afraid I'm not going to be much fun to be near tonight. In case you can't tell, I haven't had enough caffeine in the past few days and I'm feeling the need to bite my tongue a lot, it really isn't personal. I don't ever want to be away from you, I just thought this would be easier."

"Easier?" Castle questions, his hands pausing their movements on her feet.

Beckett's on the fence about how honest to be. It's easier for her to remove herself from being alone with him because then she doesn't have to think about how they can't have sex. It's also easier because she doesn't have to worry about hurting his feelings by snapping at him because she's unbelievably horny and suffering without her normal caffeine intake.

"I'm not always the most pleasant person to be around this time of the month and we were just together all day. I know I have a short temper when I'm lacking caffeine and frustrated and I just don't want to hurt you," she explains quietly. Then leans back against the arm of the couch and startles when she feels heat at her back before remembering she'd put the heating pad there.

"Please don't shoot me," Castle pauses and meets her eyes, "But Beckett I've known when you're on your cycle since way before we got together. I live with women, I know the signs, and I also know the only thing that could keep you from coffee is cramps."

Beckett blushes a little and rolls her eyes, "I'm not going to shoot you Castle. It's a good thing you never told me that before we got together though."

Castle shakes his head with a chuckle, "I'm not crazy." With that he leans down to where the tote bag he brought with him rests on the floor. "I actually brought you things that I thought might make you feel better. If you don't mind me hanging out here tonight." His adorable smile has already changed her mind about having him spend the night, not that she's going to tell him that.

"Depends on what you have in the bag Castle," Beckett says with a wink and Castle's returning grin gives her butterflies, still, after all these months. Before he reaches into the bag to pull out the items, Castle leans across and plants a kiss on Beckett's lips. She opens her mouth and responds on instinct, welcoming his tongue and quickly gets carried away in a wave of desire. It's definitely been too long since she's kissed him, stupid precinct rules.

Castle pulls back and kisses her lips briefly again. When she opens her eyes he's still there, leaning awkwardly over her knees, "Thanks for letting me stay." She rolls her eyes at him and nudges him towards his bag of goodies. He takes the hint and pulls it up onto his lap.

Castle's hand disappears into the bag and comes out with a box of chocolates, which makes her smile as he puts them down on the coffee table. Next is a bottle of Midol, followed by a bottle of wine, she laughs at that and nods towards her own half empty wine glass on the table. "So these might not be the most original items in the world, but at least I know some things that help!"

Castle defends himself as he pulls out a heating pad and Beckett responds by reaching behind herself to show him hers, "Got that one covered too Castle."

Castle smirks, "Not hiding it?" She chuckles, realizing that she just proved his point.

"Moving on," Beckett nudges him with her foot to get him to keep going, curious about what else could be in the bag.

Castle pulls out a new yoga DVD and hands it to her. "I didn't think you had that one."

Beckett smiles at him, reading the back of the DVD, which details segments for lower back pain and menstrual cramping, "Thank you, I don't."

"Okay this is the last one, are you ready?"

Beckett shakes her head with a chuckle at his theatrics.

"Hit me."

Castle pulls out season 16 of Temptation Lane on DVD and grins at her. "I thought we could maybe watch some episodes tonight?"

The gentle smile on her face tells Castle he got something right and when she nods he stands to put a DVD on. When he gets back to the couch Beckett has shifted and moved forward, leaving the spot behind her empty for him. He grins and slides in between her body and the arm of the couch, wrapping his arms around her waist as she settles back against him.

She had moved her heating pad to her stomach, but he takes it away. She opens her mouth to protest but he whispers in her ear, "Trust me, my hands will help." He presses a kiss to her neck and places his hands low on her abdomen. She feels their warmth and relaxes into his body, picking up the remote and hitting play.

When Beckett rouses a few hours later the TV screen has gone back to the DVD menu and she turns it off quickly, unable to stand the repeating Temptation Lane theme song. Castle arms are still wrapped around her, but one of his hands has crawled a bit further south to put the tips of his fingers just underneath her yoga pants, resting comfortably. The other hand moved upwards and was softly cupping her right breast. He was right, the heat of them helped; the cramps are gone and have left only arousal in their place.

She sighs, feeling her nipple hardening under Castle's hand and wishes she wasn't on her period as she settles back against his warm body. She can feel his own arousal against her back and feels heat rush through her veins. She moves just a bit to rub herself against him and he groans, his fingers pushing down on her abdomen but doesn't respond. Beckett concludes he must still be asleep and grins, dislodging his hands from her stomach as she turns around in his arms.

She rests her body against his chest and looks at the face of the man who loves her so much he didn't want to spend three nights away from her. He came prepared with presents to make sure she knew he wanted to be there. She presses a kiss to his neck and sighs, breathing in the smell of his skin; she had missed him too.

Castle lets out a moan in his sleep that she usually only hears if they're naked together and she can't help her excitement. Deciding to reward him for being such a good boyfriend, she slowly unbuttons his shirt and presses kisses to his chest as she makes her way towards his waistline. When she looks up he still looks asleep and she nips at the space between his belly button and his jeans just to test; that always breaks his cover if he's fake sleeping.

He responds by pushing his hips upwards, his hands now on her shoulders and squeezing but he still seems asleep. Beckett slowly unbuckles his belt and undoes his jeans while looking up at his face. She knows he's terrible at fake sleeping and is just waiting for him to slip up.

Satisfied that he isn't pretending, Beckett softly strokes his erection over his boxers and feels it grow while a groan comes from his mouth. She giggles, undoes the button holding the slit in his boxers together and reaches her hand inside. She gently strokes him and waits for him to wake up, but after a few minutes it seems like he is right out of it.

Pulling his penis out of his boxers, Beckett uses one hand to firmly grip the base and works her tongue over the tip. His hips jump up but his eyes don't open. She sees his hand move towards his groin and wonders if he's going to jack off in his sleep; that'd be a sight worth seeing so she backs off a little to wait. His right hand touches himself and he lets out a moan before relaxing, seemingly drifting off again.

She chuckles to herself and feels her panties dampening; thankful she put a tampon in and a pantyliner on tonight. Beckett resumes her task, running her tongue along the head of his cock before working her entire mouth over it, only stopping when she feels him hit the back of her throat. She hums in satisfaction. She loves going down on him as much as he loves doing it to her, there's something really sexy about being able to drive him crazy.

With another swipe of her tongue and a trip to the back of her throat, Castle's hips jerk up and he thrusts into her mouth as his eyes open and he looks down at her with a shocked expression. She wants to smile but her mouth is full of cock so she slowly slips it out, grinning at him and moving her tongue along the slit of his penis.

"About time you woke up Castle, joined the party," she winks at him and resumes her work, putting him back in her mouth and sucking on him gently as she deep throats him. Beckett feels invigorated by the sounds he emits as his hands move to her hair, pulling gently on it but not pushing her head down. She loves how he treats her when she's sucking him off. It's so unlike other men she's been with and it just fills her with that knowing feeling of his love for her.

She throws herself into the task and hums to herself as Castle starts saying her name, grasping her hair tighter and gently thrusting his hips. She can tell he's trying not to but she likes knowing it feels so good that his instincts take over. Beckett tastes the beginning of his release in her mouth and wishes he could be inside her cunt, but this will have to suffice.

Just as Beckett prepares herself for swallowing his cum, he surprises her by pulling her off his cock, "Beckett wait," he pants out and she can see the sweat glistening on the exposed part of his chest.

She raises her eyebrow and his face goes a bit red as he meets her eyes and firmly says, "I really want to be inside of you."

The arousal rushing through her is immediate; she wants that so badly too, it's been days.

"Castle you know I'm..." her eyes widen a little when she sees his nod, and then she realizes he doesn't care. "Really? You don't mind?"

Castle shakes his head immediately, pulling her up his body to kiss her and tasting himself on her mouth. "I want you Beckett," he murmurs against her lips and she opens her eyes to see confidence and assurance in his gaze.

"Oh thank God," she responds quickly, pulling off her shirt as Castle works at her pants. She rips Castle's shirt the rest of the way off and stands quickly to shuck off her pants from their location on her ankles. Castle stands too, pushing his jeans and boxers off, leaving them both standing naked in her living room. He grabs her body and pulls her into him, his cock still wet from her mouth and his precum rubbing against her legs. He continues to kiss her as they move towards her bedroom, kicking the door shut behind them.

She realizes she still has a tampon in just as he's pushing her down on the bed and is about to say something when he crawls on top of her, his hand moving to her center and finding it. "Do you mind if I take this out?" She can feel his hand between her legs, knows he has the string in his grasp and she's shocked by how hot she finds it that he's so confident about this. It feels very intimate and makes her feel really sexy that he wants her so unconditionally when her body feels so bloated.

She shakes her head, "Of course not." She feels him tug the tampon out, surprised by how comfortable she is with him doing something normally so private. Castle stands up off the bed and carries the used tampon into the ensuite, returning in seconds with a black towel that she knows was hanging on the bathroom door. He moves back to her body and kneels between her legs, easing her hips up enough to put the towel down underneath her before leaning up and kissing her deeply.

"There's still a box of condoms in the nightstand if you want to use one," Beckett whispers, remembering that there had been a nearly full pack in there when they had decided to stop using them regularly a couple months ago and rely on her pill. He moves his mouth down her neck to her breasts, his hand between her legs as he flicks her clit.

"Kate," he continues his exploration with his hand, but his face comes up to meet hers and she notes the dark desire in his eyes, "I want to feel you, all of you."

She acquiesces at last, stops trying to make it anything different from their normal behaviour, and nods.

"Then get inside me Castle, I've wanted you desperately for days," she breathes out and feels his gasp at her words.

With that he takes his hand away from her vagina and nudges the head of his penis there instead. He looks into her eyes as he slowly moves into her and she feels herself clench; orgasms are always the most powerful when she's on her period but usually she's the only person giving herself them.

"Oh my god Kate," Castle sighs, fully sheathed in her, "You feel amazing." He bites gently on her shoulder, nibbling his way up to her ear as he starts to move inside of her, "I feel like I haven't been inside you for weeks."

Beckett shudders, already feeling herself clench and knows she's going to cum, "Castle I'm going to cum," her hands grasp his shoulders tightly as he keeps moving inside of her as she rides out her orgasm. "Wow," she pants, "Harder, please Castle, harder. I need more." Her heels dig into his lower back, her hands fisting his hair.

Castle's hand moves to her nipple, pinching it as he thrusts into her with all of his weight, their groans quickly filling the room.

Her sensitive breasts ache with his pinches, but it's painful in a pleasurable way that shoots straight to her abdomen. She can feel another orgasm coming on and he moves his hand from her breast to her clit, pinching it and watching her face as she explodes with another, much more powerful orgasm.

"Kate," he moans into her neck, overwhelmed by the feeling of being inside her with this new shared intimacy. Feeling her intense orgasms and almost being pushed over the edge, he holds himself back only because there's one more thing he really wants to ask for. "Can I pull out and cum on you?" He's done this before, and she's enjoyed it immensely but asking first is important, especially tonight.

Beckett moans in response, nodding her head against his as she bites his collarbone, "Do it Castle, cum all over me."

He leans back, propping himself up on his elbows and kissing her as his slams his hips against her forcefully. Their mouths no longer capable of real kissing, just sharing the air in the space between their lips and breathing each other in. He can tell she'll climax again soon and is determined to make her before he releases.

"One more Beckett, cum one more time and then I'll explode all over you," he watches as she moves her own hand to her clit, using his arms to brace himself above her. He feels her inner muscles squeezing him, strangling him, and she shouts as her body shatters.

He can't hold back anymore. Just as he starts releasing he pulls out of her body and shifts to his knees between her legs. He grasps his red covered cock and finishes himself off against her cunt, spurting bursts of white all over her soaking wet body. When he sees her eyes on his hand he clenches his fist tighter on his penis, forcing the last of his arousal out.

They're both quiet for a second as they take in what just happened, Castle unable to tear his gaze away from her body covered in his cum and the evidence of her own orgasms mixed in with the red. She can see the desire in his fixation and feels an unexpectedly intense arousal go through her.

He leans forward, resting his body on top of hers and allowing his now soft cock to rub against her pelvic area. He kisses her, feels her hardening nipples against his chest and knows she might not be finished yet. "Beckett," he whispers against her lips, breaking up their soft kisses.

She hums in reply, her arms around his shoulders and hands playing in his hair. "That was amazing Castle," she scratches her nails on his scalp and smiles when he shivers against her body. "I'm always so fucking horny when I have my period but even when I've been in relationships I've had to rely on my vibrator during this time of the month."

Castle shakes his head, kissing her again, "Fools Beckett, every man you were with before me was a fool if they didn't understand how amazing you are every single day of the year." He can practically feel her eye roll, but knows his words were taken to heart because her breath stutters and her fingers gently move against his ears.

"Did you know orgasms are actually recommended to help with period pain and discomfort?" Castle is working on her neck, sucking, nipping, and licking softly.

"Was that the item you couldn't fit in your tote bag Mr. Castle?" she chuckles, then asks more seriously, "Did you come over here tonight hoping for this?"

Castle pulls back to meet her eyes, "I came over here tonight because I missed you," she can see the honesty in his gaze but quirks her eyebrow, silently asking him to continue. "I wasn't sure if you would be into it or not. I've heard some women get horny and know others don't want to be touched. I just wanted to make sure you know I always want you, but I would've been just as happy holding you all night."

Beckett smiles, lifts her hips into his, "Just as happy?"

He laughs, "Okay, not just as happy, but definitely satisfied."

She moves a hand out of his hair to caress his cheek, rubbing the spot under his eye with her thumb before leaning up to kiss him.

"I'm glad you came over Castle," she murmurs softly when they separate and is rewarded with a brilliant smile.

He hugs her, burying his face in her neck and feels like he can ask her for that one other thing he's been wanting to try. "Beckett, I'm going to ask you something and feel free to say no if it makes you uncomfortable..." he trails off with his face still resting against her neck and he feels her intake of breath before she nods. He leans up to her ear and whispers, "Can I go down on you?"

Her hands clench in his hair and she's quiet for a second as she considers, remembering the look in his eyes as he stared at the evidence of their sex on her body. She feels the incredible dampness between her legs and the tingling feeling on her clit that tells her she could definitely go another round. But... does she really want him down there right now?

Castle doesn't rush her decision, the anticipation is actually sort of turning him on as he moves a hand to her breast and carefully palms it, aware that they're overly sensitive right now. She moans softly and he pulls back to see her face, indecision in her eyes. "Beckett if you're not okay with it, I understand. I just want to make you feel good," he speaks softly as his hand strokes the skin of her stomach, underneath her breasts and up to her collarbone.

Beckett's internal debate leaves her confused; she wants him to go down on her because she always wants him to go down on her. It's practically his favorite thing to do and she loves how enthusiastically he does it. Plus if it doesn't bother him that she's on her period then it shouldn't bother her, right?

"Castle I want you to do it, I just," she tries to find the right words, "Are you sure you want to? It's not exactly the most pleasant place to be right now."

Castle almost stutters when he realizes she's into it and just needs reassurance that he really wants to, "Beckett right now your pussy is covered in my cum and yours. To me that's always the best place to be." He moves a hand over her mound and moans at the wetness and warmth of her center. "Let me get my red wings Kate," she smiles against his lips as he presses a kiss to her mouth, and when he pulls back she nods, excitement rushing through her.

Castle moves slowly down her body, his eyes flicking up to meet hers as he nips her belly button and she arches into him. When he reaches her crevice he spread her legs out further, lifting her knees to expose her completely. Beckett feels a light blush across her cheeks for the first time since Castle's first exploration of her body.

Castle's eyes are unable to move away from the view in front of him at first and Beckett thinks maybe he was doubting his decision, but when he moves his hands to her inner thighs and strokes gently, she knows he's into it.

He finally lifts his eyes to hers and holds her gaze as he moves his mouth to her center, wasting no time and giving it a long, slow, thorough lick. His entire body shudders and he feels his erection growing. He releases Beckett's heated gaze and attaches his mouth to her clit, sucking on it as she gasps and jerks her hips. He moves one hand to her stomach to hold her hips down and feasts on her cunt like he's eating a new, delicious cake he'd never tried before.

Beckett's shouts fill the room and she moves her hands to her own breasts, pinching her own nipples as Castle uses a hand to do the same to her clit. He uses his teeth and tongue on her, tasting the remnants of their sex and trace evidence of her period. It makes their cum have a slightly metallic taste to it and some animalistic part of him wants to eat it every day for the rest of his life. It feels incredibly intimate and it makes him rock hard.

He knows Beckett won't last long; she was still humming from their previous round and she seems to be even more responsive than usual right now. He flicks her clit a few times before putting two fingers deep inside her and sucking on her. Her hips thrust against the pressure of his hand on her stomach and she shouts that she's cumming.

He lets his teeth nip her clit and keeps his fingers inside her, stroking her g spot as she releases. He can feel her coming down and removes his fingers, wiping them on the now very damp towel; the thought occurs to him that's he's glad he picked a dark colored towel, he'd have hated to ruin one of her nicer ones.

He wipes his mouth on the towel too, his eyes moving up to her face but her head is thrown back from the intensity of her orgasm. He smiles proudly and moves up her body, bringing her back to him with kisses to her neck. He feels her arms around him, squeezing him tightly and her hips thrust up towards him when she feels his cock against her.

She aggressively pulls his mouth down to hers, topping from the bottom and he grins into her kiss. He loves it when she can't control her want. "Was it good for you?" he whispers against her lips, loving the dazed look in her eyes.

"Castle you are dead if you don't put your cock in me right now," Beckett's voice is anything but a whisper, the forcefulness disrupting the quiet in the room and Castle feels a chill down his spine, painfully aroused by her tone.

A verbal reply unneeded, he thrusts into her roughly and she calls out, grasping at his shoulders.

"Harder," she gasps shortly, her hips moving into his, meeting every thrust as she begs for more. "Fuck me Castle, I mean it."

Castle knows he won't be able to hold on long if she keeps talking like that. Moving to his knees and lifting her hips off the bed he pounds into her as hard as he can. Usually in this position they stick a pillow underneath her but tonight that's bypassed and he can feel his arms flexing from holding her body up.

Beckett loves his giant biceps and when she sees him holding her up by them she moans and moves to her elbows, arching her spine up to ease his load and adjust the angle so he hits her in just the right place.

It takes mere minutes for her to hit another climax, and this time she takes him with her. He releases inside of her as her body clenches and he lowers her hips, still moving within her as she grabs his body tightly.

He collapses on top of her, slipping out of her and she cradles his body with her legs and pelvis. Both panting and covered in sweat and sticky substances. It feels like an hour before either of them speak, Castle finally breaking the silence, "Have I told you lately I love how flexible you are?"

Beckett giggles lazily in post-orgasmic bliss, "Physically or sexually?"

He laughs, "You really are the perfect woman." He kisses her shoulder where his head rests, unable to move yet.

She strokes her hands up and down his back and they bask together until she looks at the clock and sees how late it is. "Castle it's nearly 2am. Let's grab a shower and go to sleep."

Castle is nearly asleep on top of her body, but his eyes open at the mention of a shower together. She immediately recognizes the look he's giving her and laughs, "No funny business Castle. I have to work in the morning."

He stands first, offering her a hand and helping her out of bed on shaky legs. He can feel the tightness in his arms from his exertion and knows they might be sore tomorrow. She kisses him gently and starts moving towards the bathroom. He watches her go and smiles when she turns back, "You coming Castle?"

He nods, "You get the shower going, and I'll throw this towel in the laundry," he gestures towards the towel on the bed. She turns into the bathroom, leaving the door open behind her. He picks the towel up and carefully folds it. Just holding it is making him want to go again; he hopes they can do this every month.


End file.
